The present invention relates to making ice. More specifically, the invention concerns a method and an apparatus for making a supply of fragmented, clear ice from one or more vertically arranged freezing plates.
One of the more practical methods of making large quantities of ice is to make large slabs of ice and then break the slabs into smaller pieces of a useable size. To create the ice slabs, vertical freezing plates may be used on which the ice slabs are formed by internally cooling the plates. The ice slabs are then loosened from the freezing plates.
Various ice making machines are in use today which utilize one or more generally planar ice plates for forming ice slabs that are subsequently broken into smaller pieces. An example of such an ice making machine is described in U.S. Pat. No. 2,995,017 issued to Breeding. Other ice making machines are utilized to form ice on structures having a variety of shapes such as pipes and molds and are found to be described in U.S. Pat. No. 3,430,452 issued to Dedriks et al; U.S. Pat. No. 2,870,612 issued to Garland and U.S. Pat. No. 2,637,177 issued to Reedall.
In the known prior art devices, however, water distribution systems have not been wholly adequate. For example, some devices use a water manifold connected with a plurality of perforated tubes to distribute water to be frozen. In such devices, the pressure drop in the tubes causes a maldistribution of water on the plates which causes non-uniform ice slab thickness and non-uniform ice quality.
It has also been difficult to obtain clear ice pieces that are generally uniform in size and free of small ice particles (often referred to as "snow"). In part this difficulty is due to the inability of prior art devices to segregate snow from large ice particles.
Typically, prior art ice making devices freeze water to make ice and then heat, in some manner, the surface on which the ice has formed so as to loosen or defrost the ice. In some devices, water is also used for defrosting purposes. When water is used for defrosting, the water must have a temperature of at least 65.degree. F. Accordingly, an auxiliary water heater and a blending valve are often part of an ice making machine.
In view of the kinds of problems discussed above, it will be apparent to those skilled in the art that there continues to exist a need for an ice making machine which overcomes those kinds of problems, as well as others.
Accordingly, it is an object of the present invention to provide a novel apparatus for making high quality, clear ice on both sides of a freezing plate to which water is supplied in a uniform manner.
It is another object of the present invention to produce ice of a generally uniform size which is substantially free of very small ice particles.
Yet another object of the present invention is to provide a novel apparatus for making ice in which snow removed from fragmented ice is recycled to precool water that is later to be frozen.
Still another object of the present invention is to use hot refrigerant gas directly from a compressor of the apparatus to defrost the ice plates and also to pressurize this hot refrigerant gas to further defrost the ice.
Yet still another object of the present invention is to provide a novel ice making apparatus having a plurality of vertically oriented ice plates arranged closely adjacent one another and including water distribution, ice sizing and removal features which cooperate with the arrangement of the ice plates to provide an ice making machine which produces a large volume of ice within a compact housing.